The present invention relates broadly to oil filters and devices used when changing vehicular oil and, more particularly, to a method and device for removing waste oil from cartridge-type oil filters immediately upon removal from the vehicle.
Cartridge-type oil filters are widely used in a variety of vehicles, ranging from automobiles to tractors. Typically, the filter will be formed as a squat, cylindrical metal receptacle with filter media disposed therein and having a rounded bottom and a cap for insertion thereonto during manufacture. A threaded pipe projects downwardly from a mounting bracket on the motor of the vehicle for contract with a mating portion on the oil filter. The oil filters are screwed on using the threaded pipe and are sealed to their mount with a circumferential gasket extending around the cap. With most cartridge-type oil filters, an internal gasket prevents oil from draining from the filter. Commonly, such cartridge-type oil filters may hold approximately one-half quart of oil which, after being circulated through the engine, becomes waste oil.
When oil in such vehicles is changed, the filter is typically inverted and allowed to drain as much as it can and then is discarded. This method leaves a significant quantity of waste oil trapped between the filter media and the outer filter casing due to the internal gasket. Do-it-yourself oil changers simply discard these filters containing waste oil in local landfills. With today's environmental concerns, any collected waste oil is no longer merely discarded but is recycled or disposed of in a predetermined manner defined by a community's environmental standards. Accordingly, the waste oil remaining trapped in a cartridge filter is newly significant. It has become desirable to remove, for collection and recycling, such waste oil from within the cartridge itself. Facilities performing oil changes send used oil filters to recyclers where the trapped oil is collected and recycled. Collecting this oil immediately at the facility would be much more efficient.
Several methods are currently in use to remove waste oil from a cartridge filter. A crude method which can be practiced without special equipment includes driving a screwdriver into the side of the filter and allowing the oil to drain through the resultant hole. This method can be messy, although it is generally successful. A variant on that method is disclosed in Kilgore U.S. Pat. No. 5,390,823. There, an oil filter hand punch provides a needle-like piercing tube for driving into the base of an oil filter and a valve in the handle for draining the oil once the drain tube is in place. This method can also be messy.
A far more complex device is disclosed in Hua U.S. Pat. No. 5,249,608. There, an apparatus is provided with the waste oil receiving pan which is commonly found in gas stations and other lubrication facilities. The Hua '608 device involves a device to force a stream of pressurized air into the filter, thereby driving the oil out. A similarly complex device is disclosed in Rozycki U.S. Pat. No. 5,214,830. According to Rozycki '830, the outer metal casing of the filter is actually severed from the cap which would, again, result in a messy arrangement.
There accordingly exists a need for a simple and effective way to drain the oil from a cartridge-type oil filter without substantial mess and without excessive cost.